Brace extension



United States Patent BRACE EXTENSION Clinton C. Nicol, New Brighton, Minn., assignor to William H. Greene, St. Paul, Minn.

Application November 9, 1953, Serial No. 391,075

Claims. (Cl. 279-89) This invention relates to an improvement in brace extensions and deals particularly with an apparatus for extending the length of a brace so that holes may be drilled at considerable distances from the operator.

In installing electric conduits and the like it is often necessary to drill holes through beams and studs which are not readily accessible. For example, in some instances it is necessary to drill through sections of a wall between the outer surface of a building and the inner surface thereof. Brace extensions are normally used for this purpose. Such a brace extension is usually provided with an end designed for accommodation into the chuck of the brace and is provided at its opposite end with a chuck designed to hold the drill. While such extensions serve their intended purpose properly, they have two disadvantages. In the first place the extension is of fixed length and accordingly several different extensions of different lengths must be used when a Wiring job of considerable size is undertaken. Furthermore, the extensions are usually made of small diameter rod and such a rod is often broken when the drill meets with resistance to rotation.

It is an object of the present invention to provide a brace extension which overcomes these previous difliculties. My brace extension includes a member designed for mounting in the brace a chuck designed to accommodate the drill. Connecting these end members is a section of thin walled tubing of the type used for the conduits. Accordingly, when a brace extension is required it is only necessary to cut ofi a length of thin walled tubing of proper dimensions and to secure it between the end portions of the apparatus.

A feature of the present invention resides in the provision of a brace extension which may be carried in a tool kit and which may be varied in length to suit each individual need. In inserting wiring, the thin walled tubing is normally used to contain the wires. Therefore, for each individual job a piece of tubing of proper length can be cut and connected between the end portions of the brace extension. After the job is completed, the end portions of the brace extension may be removed and the tubing either discarded or added to the conduit system.

A further feature of the present invention resides in the particular manner in which the tubing is connected to the ends of the brace extension. The structure is such that the end portions may expand to fill the tubing at the ends and firmly engage the tubing.

These and other objects and novel features of the invention will be more clearly and fully set forth in the following specification and claims.

In the drawings forming a part of the specification:

Figure l is an elevational view of my brace extension showing the construction thereof.

Figure 2 is a sectional view through the end of the extension which is designed for accommodation into the brace.

Figure 3 is a perspective view of the brace end of the extension removed from the tubular intermediate portion.

2,848,240 1C6 Patented Aug. 19 1958- Figure 4 is a sectional view similar to Figure 2 but showing the end member in clamping position.

The brace extension is indicated in general by the letter A. For the purpose of comparison it should be pointed out that the upper and lower portions of the apparatus as shown in Figure l are common to brace extensions now in existence. The upper portion of the extension includes a small diameter chuck 10 designed to accommodate an auger bit or drill. This chuck includes a nut-like portion 11 by means of which the chuck may be rotated and a knurled portion 12 by means of which the chuck may be adjusted by hand. The chuck includes tapered jaws 13 which accommodate the end of the bit or drill therebetween. The body of the chuck 10, together with the nut portion 11 and knurled portion 12 are threaded upon the supporting rod 14 and rotation of the chuck portion relative to the rod 14 operates the chuck.

The lower portion of the brace extension includes a tapered shank 15 of rectangular cross-section and which is designed for accommodation of the chuck and extension (hereinafter described) into the brace (not illustrated). The tapered portion 15 is connected to a rod like portion 16. In existing brace extensions the rods 14 and 16 are integral and variations in length of this rod portion 14, and 16, control the length of the brace extension.

In the present arrangement the rod 16 is threaded as indicated at 17 to accommodate a nut 19. The end of the rod extends through a first sleeve 20 and a second sleeve 21 and is anchored at 22 to the end of the sleeve 21. The adjoining ends of the sleeves 20 and 21 are diagonally cut off as shown at 23 and 24 respectively. The sleeve 20 is possessed of an opening 25 therethrough which is of somewhat larger diameter than the rod 16.

The sleeve 20 is provided at its lower end with a collar or other enlargement 26 which is secured to the sleeve 20. When the nut 19 is loosened, the two sleeves 20 and 21 are axially aligned. However, when the nut 19 is tightened, the diagonally extending sleeve ends 24- and 25 are drawn into contact and the inclined surfaces act as cams to wedge a portion of the sleeve 20 in one direction and to wedge the sleeve portion 21 in the opposite direction. As shown in Figure 3 the sleeves 20 and 21 are knurled on their outer surfaces so as to prevent slippage between parts engaged. The sleeves 20 and 21 are also of slightly smaller diameter than the inside of a section of thin walled tubing 27 such as is used in forming conduits for electrical wires. Thus, when the nut 19 is loosened as in Figure 2 of the drawings the two sleeves 20 and 21 will slide easily into the end of the tubing 27. When the nut 19 is tightened, the two sleeves are forced into slightly offset relation as indicated in Figure 4 of the drawings, thus clamping the sleeve firmly against the tubing walls. When thus engaged the tubing 27 will rotate with the tapered end 15 of the brace extension.

The rod 14 is provided with a nut 29 which is mounted upon a threaded portion 3% thereof. The rod 14 extends through a sleeve 31 identical with the sleeve 20 and is anchored at the end 32 of the second sleeve 33. The sleeves 31 and 32 are provided with diagonally extending ends 34 and 35 which act similarly to the ends of the sleeves 20 and 21. A collar 36 is mounted upon the sleeve 31 to bear against an end of the tubing 27.

In other words the upper portion, or upper end, of the device is provided with an arrangement substantially identical to the brace end of the device. By tightening the nut 29, the two sleeves may be drawn together and clamped within the tube 27 so that the chuck 10 will rotate with the tubing 27 and through the previously described structure with the brace.

Normally the upper end portion and the lower end portion, including their clamping sleeves, are carried with other tools and equipment. When it becomes necessary to drill holes of substantial length or to drill holes at a substantial distance from the brace a section of tubing 27 of the proper length to form the extension is cut. The sleeve ends of the device are then inserted in opposite ends of the tubing, in the manner described, and a brace extension of any desired length will result. After a hole is drilled, it will be apparent that the nuts 19 and 29 can be loosened and the pairs of first and second sleeves, as described, withdrawn from the tubing 27 leaving it to line the drilled hole, heretofore stated.

In accordance with the patent statutes, I have described the principles of construction and operation of a brace extension and while I have endeavored to set forth the best embodiment thereof, I desired to have it understood that obvious changes may be made within the scope of the following claims without departing from the spirit of my invention.

I claim:

1. A brace and chuck extension including in combination a pair of end member adapted to be fitted to selective disposable lengths of tubing and being separable therefrom after a drilling operation comprising a first end member having a shank designed at one end for engagement into the brace and at the other end being provided with attachable and detachable means for engaging the one end of a tubular piece of selective length, and a second end member having a chuck at one end for holding a drill and at the other end being provided with attachable and detachable means for engaging an opposite end of the tubular piece of selective length to which the said first one end member is adapted to be attached, whereby said second end member is adapted to be driven by said first end member through the medium of said tubular piece and after the completion of a drilling operation, the said end members are separable from the relative opposite ends of said tubular piece While said tubular piece is in situ as a result of the drilling operation.

2. A brace extension including an end member including a shank designed for accommodation into a brace, a second end member including a bit chuck, and a separable tubular connecting member, each of said end members including an expansible member designed to extend into and independently engage said tubular member at the ends thereof, said expansible member including a pair of sleeves having abutting inclined ends, and a threaded member secured to one sleeve and freely extending through the other, whereby upon boring a hole with said brace extension the end members may be separated therefrom and the connecting member retained in the bored hole.

3. A brace extension for use in combination with a separable section of thin walled tubing of selective length,

the extension including a pair of end members, one end member including a shank designed for accommodation into a brace chuck, and the other end member including a. bit chuck, each of said end members including an expandable member of a size to fit into the opposite ends of said thin walled tubing, each expandable member including a pair of sleeves having abutting inclined ends, and means for drawing said sleeves together, the inclined ends of said sleeves causing the same to oifset from axial alignment and bind against varying sizes of thin walled tubing.

4. A brace extension for use in combination with a separable section of thin walled tubing, the extension including a pair of end members, one end member including a shank designed for acommodation into a brace chuck, and the other end member including a bit chuck, each of said end members including an expansible member of a size to fit into the opposite ends of said thin Walled tubing, each expansible member including a pair of sleeves having abutting inclined ends, and means extending through the sleeves and anchored at the uppermost end to the end sleeves of said pairs for drawing said sleeves together, the inclined ends of said sleevescausing the same to offset from axial alignment and bind against varying sizes of thin Walled tubing.

5. A brace extension for use in combination with a separable section of thin walled tubing, the extension in cluding a pair of end members, one end member including a shank designed for accommodation into a brace chuck, and the other end member including a bit chuck, each of said end members including an expansible member of a size to fit into the opposite ends of said thin walled tubing, each expansible member including a pair of sleeves having abutting inclined ends, and means for drawing said sleeves together, said means comprising for each sleeve a threaded member anchored to one sleeve extending through the other sleeve and a member threaded onto said threaded member and engageable against said other sleeve, the inclined ends of said sleeves causing the same to offset from axial alignment and bind against varying sizes of thin walled tubing.

References Cited in the file of this patent UNITED STATES PATENTS 315,079 Shotts Apr. 7, 1885 674,528 Watson et al May 21, 1901 839,461 Eastman Dec. 25, 1906 1,028,126 Meredith June 4, 1912 1,030,592 Leland June 25, 1912 1,225,209 Beaulieu May 8, 1917 1,364,496 Weaver Jan. 4, 1921 2,280,662 Pawsat Apr. 21, 1942. 

